Professor Fekri and his research group are investigating the fundamental limits and obtaining optimal protocols for systems, networks, and mathematical models/objects resulting from the overall conduct of large collections of basic units that are confined to interact with their neighboring units. Understanding of these complicated creatures is of paramount interest in many research areas; out of which Professor Fekri's group is focused on modern error control coding (e.g., codes on graphs), sensory and cooperative systems, ad-hoc mobile mesh networks, sparse mobile (space-time and delay-tolerant) opportunistic networks, and biological networks (future research directions). Our work spans the range from theoretical foundations (e.g., delay-constrained and complexity-constrained network Information Theory), to efficient algorithms and secure/reliable protocols.